1. Field of the Invention
This invention relates to a multilayer structure and a process for the production of a multilayer structure.
2. Description of the Related Art
Molded articles made of thermoplastic resin such as polypropylene, polyester and polyamide are heretofore used widely as packaging material in the food product industry, cosmetic product industry, agrochemical industry and medical industry because of their superior mechanical properties, heat resistance, transparency, etc. In use of a thermoplastic resin molded article as packaging material, the molded article is often required to have gas barrier properties in order to prevent the content from being degraded by oxygen. As an example of such packaging material with a gas barrier property, JP 03-30944 A discloses a packaging material comprising a substrate film having thereon one layer comprising polyvinyl alcohol and synthetic hectorite, which is an inorganic laminar compound.
However, packaging materials having one layer including an inorganic laminar compound are insufficient in gas barrier properties under highly humid conditions.